Bending machine



Feb. 20, 1934 F. H. MEYER 1,948,474

BENDING MACHINE Filed Feb. 5, 1931' 3 Sheets-Sheet 1 INVENTOR F 3- Frank IiZMeyer ATTORNEYS Feb. 20, 1934. MEYER 1,948,474

BENDING MACHINE Filed Feb. 5, 1931 3 Sheets-Sheet 2 14' .15 x/ZO l F\- 19 7 \z CY: w I

NTOR F1141 H M63118) fibula 7 Wc Q? 7 ATTORNEYS Feb. 20, 1934. H MEYER 1,948,474

BENDING MACHINE Filed Feb. 5, 1931 3 Sheets-Sheet 3 INVENTOR Frank H- Meyer ATTORNEYS Patented Feb. 20, 1934 UNITED STATES PATNT FFICE BENDING- MACHINE Application February 5, 1931. Serial No. 513,616

10 Claims.

This invention relates to pipe bending machines and more particularly to the dies which form a part thereof.

One of the objects of the present invention is to provide an improved bending machine of such construction that tubular members can be bent to the desired shape with great efficiency and in a minimum of time.

Another object is to provide an improved pipebending machine in which tubular members can be bent to shape without the use of bearing members or fillers.

Another object is to provide a pipe-bending machine in which tubular members can be bent without wrinkling while preserving the original cross-sectional shape of the tubular member.

Another object is to provide pipe-bending dies which cooperate in such a manner that they gradually engage and bend a section of the tubular member in a lengthwise direction.

Another object is to provide a pair of pipebending dies each of which is movable relative to the other and which cooperate to progressively bend adjacent increments of a tubular member.

Another object is to provide a pair of cooperating bending dies, one of which comprises resiliently supported pivoted members which cooperate with the other die to progressively bend increments of a tubular member without wrinkling, while preserving the original cross-sectional shape of that member.

Another object is to provide a pair of cooperating bending dies, one of which comprises resiliently supported members cooperatable separately with the other die to progressively bend adjacent increments of a tubular member.

With the above and other objects in view which will be apparent from the detailed following description, the present invention consists in certain features of construction and combination of parts that will be readily understood by those skilled in the art to which the invention appertains.

In the drawings which illustrate suitable embodiments of the present invention,

Figure l is a front elevation of the pipe-bending machine;

Fig. 2 is a side elevation of the pipe-bending machine shown in Fig. 1;

Fig. 3 is an enlarged elevation of that portion v of the bending machine comprising the cooperating dies, the dies being shown in position ready to form a bend in a piece of tubing, portions of the dies being broken away to show the tubing lying within the die recesses;

Fig. 4 is a view similar to Fig. 3 with the exception that the positions of the dies have been changed to that position corresponding to a position in the bending operation;

Fig. 5 is an end view of the apparatus shown in Fig. 3, portions of the same being shown in section to illustrate the cooperating features of parts thereof;

Fig. 6 is an enlarged section taken substantially on line 6-6 of Fig. 4 showing the cooperating engagement between the upper die and one of the die blocks during the bending operation;

Fig. 7 is a side elevation of die members of a modified bending machine;

Fig. 8 is a view of the same parts as shown in Fig. 7 with the exception that they are shown in the process of bending a piece of tubing, portions of the same being broken away and shown in section; and

Fig. 9 is an end View of the apparatus shown in Fig. 7, portions of the same being broken away and shown in section.

Referring to the accompanying drawings in which like numerals refer to like parts throughout the several views, the dies of the present in-' vention are shown for the purpose of illustration as carried by and brought into operative relation by a hydraulically operated device, it being understood that they may be used in connection with bulldozer machines or any other suitabl machine.

As shown in Figs. 1 and 2, the apparatus supporting the dies comprises a supporting member 1 having a lower die supporting bracket or base 2 and a cylinder 3 spaced upwardly therefrom within which a hydraulically operated piston 4 is arranged to reciprocate. A suitable piston rod or ram 5 is carried by the piston 4 to extend through the end of the cylinder 3. The upper die 6 is very securely mounted in any desired manner such as by the cap screws 7, on the free end of the ram 5.

The die 6 a work-engaging recess 8, which, as shown in Fig. 6, is of semi-circular shape in cross-section, the axial curvature of which conforms to the bend to be formed in the tube 9. This particular recess 8 is arranged to contact with the tube throughout substantially 180 degrees of its circumference when the tube is completely bent, in order to form a bend of substantially 180 degrees.

The working faces of the recesses 8 are formed with plane continuation faces 10 tangent thereto which diverge substantially from the diameter of the recess 8. The peripheries of the metal comprising the faces 10 are also semi-circular and have the same axis as the recess 8. These faces 10 cooperate with corresponding faces on the die blocks to be later described.

The lower die comprises a pair of die members carried by a base 11 which is secured to the frame bracket 2 by set screws 12. The die members each comprises a die block 13 secured by countersunk screws 14 to a slide 15, the slide 15 having divergent ways which cooperate with and slide in a recess provided in a supporting block 16. Each supporting block 16 is mounted on the bottom of a U-shaped support 17 by means of spaced bolts 18 carried by the bottom of the support 1'7, as shown in Figs. 4.- and 5, and which have upwardly divergent heads that are seated in dovetail grooves 19 formed in the supporting blocks 16. The bolts 18 when tightened securely clamp the blocks 16 to the supports 1'? through the medium of the bolt heads and grooves 19. The blocks 16 may be moved relative to the support by loosening the bolts 18, thus providing longitudinal adjustment of the die blocks 13 and supports 16 on the members 17.

Each U-shaped support 17 is pivoted by means of suitable pins 20 to legs of a U-shaped bracket 21 adjustably mounted on the base 11 by means of suitable cap screws 22. The screws 22 extend through a slot 23 in the base 11, and are threaded into a clamp plate 24 positioned on the lower side of the base 11. It is obvious that by loosening the cap screws 22 the bracket 21 may be moved to any desired position on the base 11.

Two such supporting brackets 21 are mounted on the base 11 and are so arranged that the ends of the die blocks 13 abut against each other substantially on the axis line of the ram 5, as shown in Fig. 3. The adjustment just described is provided so that when longer or shorter die blocks 13 are employed the brackets 21 may be moved to the proper position for any given condition.

As previously mentioned, the die blocks 13 are resiliently mounted so that normally they form substantial continuations of each other, as shown in Fig. 3. The pins 20 which pivot the supporting members 17 to the brackets 21 extend well beyond the legs of the member 21 and each is formed with a crank arm 25 at its opposite end, which crank arm extends downwardly at an angle away from the abutting ends of the die blocks 13. Links 26 are hinged by means of pins 27 to the opposite crank arms 25 of each pin 20 and extend downwardly at the sides of and to a point below the base 11. The lower ends of the links 26 are interconnected by means of a bar 28 having a spring plate 29 rigidly mounted thereon. A suitable heavy compression spring 30 preferably of the coil type is mounted between the plate 29 and the clamp plate 24, and is continuously under compression which, because of the links 26 and crank arms 25, resiliently holds the cooperating die block 13 in the normal horizontal position shown in Fig. 3. If desired, suitable guide means 31 may be provided within the spring 30.

Each die block 13 is formed with a longitudinal recess 32 that is semi-circular in cross-section. The sides of the block 13 are slightly convergent so that they will fit within and cooperate with the faces 10 of the upper die 6, and terminate substantially at the edge of the recess 32 in substantially a feathered edge. When the die 6 and die block 13 are brought into cooperative closed position, as shown in Fig. 3, the recess 8 of the die 6 and recess 32 of the die block 13 unite to form an unbroken contour which prevents wrinkling of the tube being bent, since the tube before and after bending completely fills the space provided by the recesses 8 and 32 with the result that no spaces are provided for the distortion of the tube, so that during the bending operation. movement of the metal can only occur within a fixed diameter.

It will be particularly noted in Figs. 4 and 6 that the parting line of the die 6 and die block 13 is on a diameter of the tube to be bent, and furthermore, that the recess in the upper die 6 only conforms to the final curvature of the tube' being bent or to be bent, the recesses 32 in the die blocks 13 being longitudinal.

In operation, the tube 9 to be bent to shape, which shape as shown in Figs. 3 and 4 is to be a curvature of substantially 180 degrees, is positioned within the recesses 32 formed by the die blocks 13 which are normally in a contiguous coaxial relation. The ram 5 is lowered and before any bending whatsoever occurs the die 6 carried by the ram cooperates with the two pivoted die blocks 13 and completely encloses the tube substantially at the axis of the ram 5. In this position and in any subsequent position the side faces of the die blocks 13 engage with the faces 10 of the upper die 6, and the feathered edges of the die blocks 13 engage with a main face on the die 6 to form a continuous opening, thus completely enclosing the tube 9.

As the die 6 is moved against the die blocks 13, the lower die members gradually pivot about the axes of the pins 20, the pressure of the springs 30 resisting such pivoting movement. Because of the curved upper die and the pivoting movement of the straight lower die blocks, the contact between the die 6 and die blocks 13 gradually changes and moves outwardly away from the axis line of the ram 5, thus causing the tube 9 to be bent progressively outwardly from a central point into the recess 8 of the die 6. The tube is prevented from wrinkling during the bending operation because of the progressive bending of small increments of the tube and because at the instant of bending any increment, such increment is confined within the circumference of predetermined diameter. During the bending operation the supporting members 15 for the block 13 may or may not slide relative to the U-shaped portions 16, this movement being dependent somewhat upon certain conditions such as the diameter and radius of curvature of the tubes to be bent.

The principal feature, however, is the function of the die block 13 and die 6. The die blocks 13 pivot during movement of the die 6 and tend to wrap the tube 9 into the recess 8 of the die 6. Each die block 13 in order to do this during a bending operation is always in engagement with the section or increment of the tube being bent at the time of bending. Furthermore, the die 6 is always in engagement with any increment of the tube being bent, at the time of bending.

It is unnecessary in an apparatus of the type described to provide bearings or fillers within the tube being bent in order to prevent wrinkling or distortion of the tube, and it is obvious that the elimination of this objection is very advantageous principally because of the saving in time and the saving of labor.

In Figs. '7 to 9, inclusive, a modified type of arrangement is shown, the apparatus being arranged to form a bend of substantially 120 degrees in a tube 52. In this construction the die blocks 40 are secured directly to supports 42 by means of suitable screws 41, the supports 42 being formed at their outer ends with spaced upwardly extending arms 43. The arms 43 of the supports 42 are pivoted by means of pins 44 to supporting brackets 45 which are adjustably mounted on a base portion 46. The inner ends of the supports 42 abut against each other and also rest upon a common pressure pad 4? as shown in Fig. 8, the pad 47 being held in normal position up against the ends of the supports 42 by a single compression spring 48. This spring 48 is placed in compression by means of a lower plate 49 which is secured by means of set screws 50 to the bottom portion of the base 46. The upper die 51 and the die blocks 40 are formed in identically the same manner as the die 6 and die blocks 13 of the construction previously described, and the apparatus functions in substan-- tially the same manner.

During the bending operation the tube 52 lies within the recesses formed within the dies and is progressively bent outwardly from a central portion. During this operation the die blocks 40 pivot downwardly against the pressure of the spring 48 with the result that the die blocks 40 progressively wrap small increments of the tube 52 being bent into the recess formed in the upper die 51. At the instant of bending of any increment of the tube 52, such increment is simultaneously engaged by one of the lower die blocks 40 so that the blocks 40 can wrap the increment into the recess of the upper die 51.

It is to be noted from the drawings and the foregoing description that during the entire bending operation there is a continuous engagement between the upper die 51 and the lower die blocks, although the point of engagement of the die blocks 40 gradually changes as the lower die blocks pivot, this change occurring from the intermediate portion outwardly toward the end of the bend being formed in the pipe.

The recesses in the faces of the die members may be of various shapes in cross-section, and I do not limit my invention to the curved crosssection illustrated in the drawings. It is also clearly apparent that the relation of the upper and lower die members may be reversed so that the pivoted die members may be pivoted to the ram in any suitable manner to accomplish the same result hereinbefore set forth.

Aside from the specific embodiments of the invention herein shown and described, it will be understood that numerous details of the construction may be altered or omitted without departing from the spirit and scope of this invention. I do not desire to limit the invention to the exact construction herein set forth, as I desire to claim the same broadly as well as specifically, as indicated in the appended claims.

What I claim is: i

1. In a tube bending machine, a pair of pivotally supported die blocks, each having a recess coaxial with the other for supporting a tube to be bent, resilient means normally resisting pivotal movement of said die blocks, a movable die having a recess corresponding in shape to the bend to be formed, and means for moving said die into engagement with said die blocks whereby said die blocks can pivot against the resistance of said resilient means and bend the tube into changed during the bending operation.

2. In a tube bending machine, a pair of pivotally supported die blocks, each having a recess coaxial with the other for supporting a tube to be bent, resilient means normally resisting pivotal movement of said die blocks, a movable die having a recess corresponding in shape to the bend to be formed, and for moving said die into engagement with said die blocks wt ereby said die blocks can pivot against the re stance of said resilient means and bend the tube into the recess of said di the recess of each said die block and the recess of said die the instant of bending of any increment of the tube being to combine and completely surround the tube to confine the same within a passageway of predetermined diameter.

3. In a tube bending machine, a pair of pivotally supported die blocks, each having a recess coaxial with the other for supporting a tube to be bent, resili nt means normally resisting pivotal movement of said die blocks, a movable die having a recess corresponding in shape to the bend to be formed, and means for moving said die into engagement with said die blocks whereby said die blocks can pivot against the resistance of said resilient means and bend the tube into the recess of die, said die each said die block at the instant of bending of any increment of the tube having overlapping portions to confine the tube within a passageway of predetermined diameter.

4. In a tube bending machine, a movable die having a tube engaging recess therein conforining to the shape of the bend to be formed in a tube, resiliently supported means having a tube engaging recess therein conforming to the original shape of the tube to be bent, and means for moving said die against said resiliently supported means and for subsequently moving both said die and resiliently supported whereby said resiliently supported means may bend the tube into the recess of said die.

5. In a tube bending machine, a movable die having a tube engaging recess therein conforming to the shape of the bend to be formed in a tube, resiliently supported means having a tube engaging recess therein conforming to the original shape of the tube to be bent, and means for moving said die against said resiliently supported means and for subsequently moving both said die and resiliently supported means, the engagement of said resiliently supported means with said die during the subsequent movement of both said die and means being continuously changed whereby adjacent increments of the tube are progressively bent by said resiliently supported means into the recess of said die.

6. In a tube bending machine, a pair of dies each movable relative to the other and each having a recess therein conforming to one-half of the periphery of the tube to be bent, one of said dies having its outer side faces tapered and substantially joining with the face of its recess in substantially a feather edge, and the other of said dies having inclined faces continuing from the face of the recess therein, the side faces of the one die being engageable with the inclined faces of the other die to provide a closed tube receiving space having a continuous tube engaging wall of the same periphery as the tube being bent.

'7. In a tube bending machine, a base, a pair of spaced supports secured to said base, an arm pivoted to each support, means resiliently holding said arms in axial alignment, a die block secured to each said arm and having a longitudinal tube supporting recess therein, a movable die having a recess therein conforming in shape to the bend to be formed in a tube, and means for moving said die into engagement with said die blocks and subsequently moving both said die and die blocks to bend the tube into the recess in said die.

8. In a tube bending machine, a base, a pair of spaced supports secured to said base, an arm pivoted to each support, means resiliently holding said arms in axial alignment, a die block secured to each said arm and having a longitudinal tube supporting recess therein, a movable die having a recess therein conforming in shape to the bend to be formed in a tube, and means for moving said die into engagement With said die blocks and subsequently moving both said die and die blocks to bend the tube into the recess in said die, the engagement between said die and each said die block being continuous from the instant of initial bending to the completion of the bending operation.

9. In a tube bending machine, a base, a pair of spaced supports secured to said base, an arm pivoted to each support, means resiliently holding said arms in axial alignment, a die block secured to each said arm and having a longitudinal tube supporting recess therein, a movable die having a recess therein conforming in shape to the bend to be formed in a tube, and means for moving said die into engagement with said die blocks and subsequently moving both said die and die blocks to bend the tube into the recess in said die, the engagement between said die and each die block being continuous from the instant of initial bending to the completion of the bending operation, said engagement being progressively moved outwardly from the point of initial bending to the point of final bending.

10. In a tube bending machine, a base, a pair of spaced supports secured to said base, an arm pivoted to each support, said arms normally being in axial alignment, a resiliently supported pressure pad for supporting adjacent free ends of said arms, a die block secured to each said arm and having a longitudinal tube supporting recess thereon, a movable die having a recess therein conforming in shape to the bend to be formed in a tube, and means for moving said die into engagement with said die blocks and for subseqently and simultaneously moving both said die and die blocks to bend the tube into the recess in said die, said subsequent movement also causing relative movement between said die blocks and die.

FRANK H. MEYER. 

